크랙幅이 壓縮破壞强度에 미치는 影響

文秉秀,黃秀喆,吳範錫,趙鎭境 충북대학교 산업과학기술연구소 2002 산업과학기술연구 논문집 Vol.16 No.1

Under the compressive loads, tensile stress fields are possibly induced according to the boundary condition of compressed body. At the crack tip, the possibility of occurance of tensile stress fields are strong even under the compressive loads. In this paper, the fracturing behavior of brittle materials containing crack are investigated and the compressive strength affected by crack clearance are inspected theoretically and experimentally. Upon the theoretical and experimental results, it is found that compressive strength is decreased as the crack clearance is increased.

위절제술 후 Carboxy-Methylcellulose를 이용한 위장관 조영술

오재천,김용수,문원진,임현철,고병희,조온구 한양대학교 의과대학 1997 한양의대 학술지 Vol.17 No.1

The purpose of this study was to determine the usefluness of the UGI study with Carboxy-Methylcellulose (CMC) and 140% barium in the patient undergone gastrectomy We reviewed the UGI study with effervescent agent and barium and the UGI study with CMC and 140% barium of twenty one patients, undergone gastrectomy (Billroth-Ⅱ:12, Billroth-Ⅰ:4 total gastrectomy:5). The average interval between these studies was 19 months. The coating quality of the remnant stomach, anastomosis sit e, jejunum and proximal ileum in two studies were compared. The maximum luminal diameter of the same site and the maximum distance between a adjacent valvulae conniventes were measured for evaluating the distensibility of these studies. Compared with the coating quality of the remnant stomach, the UGI study with effervescent agent and barium was superior to the UGI study with C MC and barium in 68% (11/16) patients. The difference of coating quality between these studies was marginal in the anastomosis site and jejunum. The UGI study with CMC and barium provided a better coating quality in the proximal ileum of 95%(20/21). The maximum luminal diameter of the anastomosis site, jejunum and proximal ileum was respectively 2.75cm, 3.36cm, and 2.82cm inthe UGI study with effervescent agent and barium, 3.2cm 3.35cm, and 3.40cm in the UGI study with CMC and barium(p〈0.01). The maximum distance between a adjacent valvulae conniventes of the jejunum and proximal ileum was respectively 0.61cm and 0.51cm in the UGI study with effervesent agent and barium, 0.74cm and 0.72cm in the UBI study with CMC and barium (p〈0.05). Compared with the distensibility, the UGI study with CMC and barium was superior. The UGI study with CMC and barium in subjects, undergone gastectomy, showed the advantage the mucosa distal to anastomosis site except for the remnant stomach and must be supply the more information in finding lesion such as adhesion and peritoneal dissemination.

백서에서 Depulpin®과 Formocresol에 대한 치수와 치근단 조직의 반응

문형인,김선호,황윤찬,오병주,황인남,김선헌,정선와,윤창,오원만 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.4

One fifth dilution of formocresol is usually for pulpotomy of the primary teeth and emergency pulpotomy of the permanent teeth. However, the use of formaldehyde has been subjected to criticism because it may be absorbed into the blood stream and become distributed systemically, it may also alter the pulp tissue rendering it immumologically active, and have carcinogenic potential. Recently Depulpin®(VoCo., Germany) gains popularity as a devitalizing agent during root canal therapy in spite of high concentration of 49% paraformaldehyde because it facilitate devitalization of pulp and make root canal therapy easier. But there have been not enough publications about the reaction of pulp and periapical tissue caused by Depulpin. This study was performed to evaluate the histological changes in pulp and periapical tissue of rats after pulpotomy using formocresol and Depulpin and to elucidate the toxic effects of these agents. Thirty six Sprague-Dawley rats were anesthetized by intraperitoneal injection of ketamine. Maxillary first molar teeth were used for pulpotomy with formocresol and Depulpin. Rats were sacrificed after 2 days, 4 days, 1 week, 2 weeks, 3 weeks and 4 weeks respectively. Specimens were histologically observed by light microscope changes in pulp and periapical tissue. The obtained results were as follows. 1. Formocresol group A zone of fixed tissue, in which odontoblasts could clearly be defined, was present directly underneath the pulpotomy dressing in almost all teeth of this group. This was followed by an area of necrotic tissue which resembled dried out fibrous tissue with no cellular detail except some pyknotic nuclei. In the specimens of after 2 days, 4 days, 1 week, 2 weeks in which vital tissue was present. it was separated from the fibrous area by a zone of inflammation. In the specimens of after 3 weeks and after 4 weeks, inflammatory infiltrate was in the periodontal ligament adjacent to the apical foramina of the teeth. 2. Depulpin® group The area of necrotic tissue which had no cells and fibers , was present adjacent to the dressing. This was followed by dried out fibrous tissue with no cellular details except some pyknotic nucleli. A short stump of vital pulp with odontoblasts was present at the end of the canal after 2 days. Inflammatory infiltrate was in the periodontal ligament after 4 days and after 1week. Severe root resorption and necrosis of periapical tissue opposite the root resorption site were defined after 2 weeks and after 3 weeks. Periapical lesion which consist of necrotic tissue surrounded by a fibrous connective wall. was found after 4 weeks. The results indicated that Depulpin can cause more adverse reaction to the dental pulp and periapical tissue than formocresol, and further studies are needed for its clinical use with safety.

The prediction of the tooth size in the mixed dentition for Korean

Moon, Sung-Hwan,Kim, Seong-Oh,Yu, Hyung-Seong,Choi, Byung-Jai,Choi, Hyung-Jun,Lee, Jae-Ho 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.2

이번 연구의 목적은 혼합치열기 아동에서 미맹출된 견치와 소구치의 크기를 예측하는데 있어서 한국인에 맞는 방정식을 만들기 위함이다. 미맹출 치아의 크기를 예측하는 것은 혼합치열기 교정 진단과 치료계획 수립에 있어서 매우 중요하다. 미맹출된 견치와 소구치 크기를 예측하는 방법은 몇가지가 있지만 그중에서도 가장 흔하게 쓰이는 것이 모이어의 예측표와 다나카와 존스턴의 방정식이 있다. 하지만 그것들은 백인을 위해서 제작된 것이고 치아 크기는 인종에 따라서 다르다고 알려져 있다. 이번 연구에서는 치아크기를 측정하여 하악 영구 절치의 크기 합과 견치 및 소구치의 크기 합 사이의 상관관계를 구하고 회귀방정식을 이용해서 한국인에 맞는 예측표를 만들었다. 연세대학교 치과대학에 재학중인 178명의 한국 학생(남 108명, 여 70명, 평균연령 21.63)을 대상으로 실험하였다. 영구치의 근원심 폭경을 석고모형상에서 calipers를 이용해서 측정하였다. 성별간의 치아 크기는 차이가 있었다(p<0.05). Correlation coefficient는 0.57에서 0.64의 범위였고, standard errors of the estimates 는 여성에서 0.6으로써 남성보다 우수하였다. r^(2)값은 0.27에서 0.41의 범위를 나타내었다. Estimating the size of unerupted teeth is an essential aspect of orthodontic diagnosis and treatment planning in the mixed dentition. Several methods were introduced and used for the prediction. The most common methods among these would be Moyers probability chart and Tanaka and Johnston equations. These are currently used widely, but they were developed for Caucasians. Because there are clear racial differences in teeth size, the objectives of this study were to produce correlation coefficients between the combined mesiodistal widths of the permanent mandibular incisors and those of the canines and premolars for each quadrant, and prediction tables with regression equations, specifically for Korean. 178 young adults (70 women, 108 men, mean age 21.63 years) were selected from the College of Dentistry, Yonsei University, Seoul, Korea. The mesiodistal crown diameters of the permanent teeth were measured with calipers. Significant sexual dimorphism was found in tooth sizes. The correlation coefficients between the total mesiodistal width of the mandibular permanent incisors and those of the maxillary and mandibular canines and premolars were found to be between 0.52 and 0.64. The standard error of the estimatation was better (0.60) for women and the r^(2) values ranged from 0.27 to 0.41 for both sexes, Prediction tables were prepared for Korean. This study showed larger canine and premolar diameters than Tanaka and Johnston's and Moyers' studies which might be due to the racial differences. Further investigations with a larger sample size will be needed for more representative data on the Korean population.

이소성 타액선에 의한 경부 누공 1예

김병균,김문범,이재봉,오창근,장호선,권경술 대한피부과학회 2003 대한피부과학회지 Vol.41 No.3

Ectopic salivary tissue is an uncommon etiology of a neck mass in an infant. It is due to anomalous embryologic development of salivary tissue. We have experienced a case of cervical fistula due to ectopic salivary gland in 3-year-old male. The discharge is saliva-like and related to meals. Histopathologically, mucinous acini are located in lower dermis and subcutaneous fat. When a cystic neck mass or fistula is present on cervical area especially in children, an ectopic salivary gland should be considered as one of the causes. (Korean J Dermatol 2003;41(3) : 394∼396)

영아의 상순에 발생한 유피낭종

김성오,문성환,이제호,최형준,최병재 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.3

유피낭종(dermoid cyst)은 표피형태의 상피세포로 이루어진 낭종의 벽에 피부부속조직을 포함하는 발생학적 낭종이다. 눈썹 부근이나 구강저의 중심선에 호발하지만 혀, 입술, 협점막의 병소도 보고된 바 있다. 이 병소는 천천히 커지고 무통성이며 임파선비대는 동반하지 않는다. 내용물은 피지성, 화농성등이며 크기는 수 mm에서 12cm까지 다양하다. 조직학적 특징은 상피세포 이장과 낭종벽내의 땀샘, 피지샘, 모낭동의 피부부속조직의 존재이다. 유피낭종의 치료는 완전절제이다. 완전한 절제시 재발의 가능성은 거의 없다. 본 증례의 2세 여자 환아는 1년 전에 넘어진 이후 상순에 딱딱한 것이 생겼다는 것을 주소로 연세대학교 치과대학병원 소아치과에 내원하였다. 임상 구강검사 결과 둥근 고무질감의 종괴가 상순에서 관찰되었다. 조직학적 검사를 위해 조직생검을 시행하였으며, 낭종의 벽에서 피지샘이 관찰되었다. 이에 상순에서는 드물게 발생하는 유피낭종으로 진단되어 보고하는 바이다. Dermoid cyst is a developmental cyst that is lined by epidermis-like epithelium and contains dermal adnexal structures in the cyst wall. Dermoid cyst most occur in the eye brow although occasionally develop in other locations such as midline of the floor of the mouth, tongue, lip and buccal mucosa. The lesion is slow growing and painless without lympadenopathy. The contents of the dermoid cyst can be caseous or sebaceous. The size can vary from a few millimeters to 12cm in diameter. Histologically, dermoid cyst is lined by epidermis and adnexaes such as sweat gland, sebaceous glands and hair follicles are present in the cyst wall. The 2-year-old female of this case visited Department of Pediatric Dentistry, College of Dentistry, Yonsei University with a chief complaint of the emergence of mass on her upper lip. An excisional biopsy was carried out for a histological examination and sebaceous gland was observed in the cyst wall. The lesion was diagnosed as dermoid cyst. Delmoid cyst does not recur if complete excision is accomplished.

부정교합 아동의 성장에 따른 연조직 측모의 변화

권오원,경희문,장병천,성재현,김정민 대한치과교정학회 1989 대한치과교정학회지 Vol.19 No.3

This investigation was undertaken to know how soft tissue facial profile could changed with age. The 3 serial lateral cephalometric roentgenograms of the twenty nine boys and twenty six girls between 9 and 13 years of age were studied and the findings seemed to warrant the following conclusions. 1. The author made the tables of means, standard deviations in each item, sex, age. 2. Soft tissue facial angle, soft tissue facial convexity including the nose tended to increase, but others tended to remain relatively stable. 3. Facial soft tissue thickness increased with age and the growth of facial soft tissue in the middle rgion (point A, LS, LI)was greater than others in the facial region. 4. In the soft tissue vertical proportions, GI'-Sn/Sn-Me' was 1.1, Sn-St/St-Me' was 0.51:1, Sn-LI/LI-Me' was 0.82.1 and those were stable with age.

간세포암과 감별이 어려웠던 악성중피종 치험 1예

김선문,허원석,채경훈,강윤세,정재훈,김연수,박기오,문희석,이엄석,김석현,성재규,이병석,이헌영,신경숙,조준식,송인상,강대영 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Malignant peritoneal mesothelioma is a rare neoplasm that arises from the mesothelium of a serosal cavity and is a rapidly fatal disease with a median survival of 4 to 12 months for untreated cases. Recently, we experienced a case with malignant peritoneal mesothelioma who was suspected hepatocelluar carcioma by abdominal CT scan and was confirmed by biopsy including immunohistochemical stain(calretinin) after surgery. We performed tumor excisions and wedge resection of the liver(segment Ⅷ)and inserted Tencoff catheter in abdominal cavity at 25th day of post-operation. We treated with intraperitoneal paclitaxel(25mg/m^(2)/day for 5 days) six courses monthly. She was well tolerable and is still living without any evidence of recurrence for 14th month of post-operation.

단계적 온도 하강법을 이용한 췌도세포 냉동보존법

정인경,오승훈,김병준,양태영,이병완,하창영,노정현,정재훈,민용기,이명식,이문규,김광원 대한당뇨병학회 2002 Diabetes and Metabolism Journal Vol.26 No.1

연구배경:최근 당뇨병의 새로운 치료법으로 시도되고 있는 췌도이식은 충분한 췌도수의 확보와 췌도생존율을 높이기 위한 면역억제제 사용이 제한점이 되고 있다. 본 연구의 목적은 이식 전 충분한 췌도 수의 확보를 위해 분리한 췌도를 냉동보존하는 방법을 확립하고 냉동보존한 백서 췌도세포의 시험관내 그리고 생체내 기능을 조사하였다. 방법:분리한 백서의 췌장소도를 48시간 배양한 후 한 시험관당 췌도세포 1000개씩 나누었다. 냉동보존은 6개의 시험관에 DMSO를 첨가한 후 초 냉각(supercooling), 핵화(nucleation)단계를 거친 후 99% isopropanol과 액체질소가 들어있는 dewer를 이용하여-0.25℃/분의 냉각속도로 -40℃까지 단계적으로 얼린후-70℃ 액체질소 탱크에 보관했다. 해동은 냉동시킨 vial들을 액체 질소 태으에서 꺼내 37℃ 항온조에 담가 급격히 해동시킨 후, 원심분리하여 상층액을 제거하고 각 vial에 0.75M sucrose 용액을 가한 후, 10% fetal calf serum이 함유된 RPMI 1640 media에서 배양하였다 각각 6개의 시험관에서 해동한 췌도들을 광학현미경 및 형광현미경하에서 췌도의 모양과 생존율에 대해 조사하고 인슐린 정적반응을 알아보았다. 또한 분리한 췌도를 냉동보존하지 않고 이식한 경우를 대조군(6마리)과 생체내 기능을 비교하였다. 결과:① 냉동보존후 획득한 췌도의 수와 생존율 해동후 획득한 췌도의 수는 해동시킨 당일날이 902±21, 24시간 배양 후에는 857±16, 72시간 후에는 817±18개로 점차 감소되었다. AO/PI 염색상 각 췌도의 생존율은 냉동 전을 100으로 하였을 때 해동당일, 24시간 후, 72시간 후가 각각 60±5, 80±5, 90±5%로 해동후 3일간 배양하였을 때 냉동전의 수준으로 회복하였다. ② 냉동보존후 췌도의 포도당에 대한 정적 인슐린 분비능:냉동직후 감소된 경향을 보였으나 해동후 3일간 배양한 췌도의 인슐린 분비는 냉동전과 통계적으로 의미있는 차이가 없이 냉동보존 전의 수준으로 회복되었다. ③ 냉동보존후 췌도의 포도당에 대한 동적 인슐린 분비능:냉동보존한 췌도를 해동후 3일째의 인슐린 동적 분비능은 냉동 전과 마찬가지로 자극 인슐린의 반응의 제1기와 2기가 잘 관찰되었다. ④ 냉동보존한 췌도세포 이식 후 혈당 변화:스트렙토조토신으로 유도된 당뇨병 쥐에 췌도이식 후 혈당은 냉동보존한 췌도이식군에서 대조군에 비해 혈당의 조절효과가 더 오래 지속되었다. 결론:소동물에서 단계적 온도 하강법을 이용한 췌도세포 냉동보존법을 확립하였으며 이는 기능, 구조 및 생존율에 큰 이상을 보이지 않았으므로 장차 사람의 췌도세포 동종이식시 부족한 췌도세포수를 극복하고 면역반응을 줄일 수 있는 매우 유용한 방법이 될 것으로 판단된다. Background : Although islet transplantation has been attempted to reverse the state of diabetes, achieving a critical number of islets and modulating the immune response limit the success of islet transplantation. Cryo-preservation of islets offers many important benefits for islet transplantation by collecting islets with a wide variety of HLA phenotypes and islet MHC expression. The aims of this study was to determine the optimal conditions for cryo-preservation by using a controlled cooling method and to evaluate in vitro and in vivo functional properties of the cryo-preserved islets. Methods : Collagenase-isolated, Ficoll-purified islets were cultured for 48 hours. They were aliquoted into freezing tubes (1000 islets per tube), equilibrated with 2M dimethyl sulfoxide (DMSO) in three steps, supercooled, nucleated, and controll-cooled at rate of 0.25℃/min to - 40℃ prior to storage at - 196℃. Rapid thawing and removal of DMSO with 0.75 M sucrose preceded 48 hour of culture and the morphology, viability, glucose-induced insulin secretion, and in vivo function of rats transplanted with cryopreserved islets was reexamined. Results : ① Recovery was 90.2±0.2%, 85.7±0.1% and 81.7±0.1% immendiately after, 24 hours and 72 hours after thawing respectively. The viability was 60±5%, 80±5%, 90±5% immediately after, 24 hours and 72 hours after thawing respectively. ② The glucose-stimulated-insulin secretion (GSIS) tended to decrease immediately after thawing, but GSIS increase to the level of pre-cryopreservation 72 hours after thawing. ③ The in dynamic GSIS, the first and the second phase of insulin secretion were well preserved in islets cultured for 72 hours after thawing. ④ The cryopreserved islets were cultured for 3 days and transplanted into renal sub-capsular space of streptozotocin (STZ) induced diabetic rats. The duration of normoglycemia in the STZ-induced diabetic rats transplanted with cryopreserved islets was significantly longer than of the fresh islets. Conclusion : The optimal condition of cryopreservation using the controlled cooling method was established in rat pancreatic islets. This cryopreservation method can be a feasible approach for human islet transplantation (J Kor Diabetes Asso 26:64~74, 2002).

Double scanning 방식을 적용한 X-ray video converter 개발

이채욱,문병현,오신범 大邱大學校 科學技術硏究所 1999 科學技術硏究 Vol.6 No.1

With the rapid development of medical technology, the digital radiological imaging techniques, such as CT, MRI, PET, CR and X-ray, have been widely used. The demand of medical image storage and noiseless signal requires good video converter system. In this paper we develop a new x-ray video converter using double sunning method. This converter can simplify the monitoring system and improve the image enhancement.